source-engine/game/shared/shot_manipulator.h
2023-10-03 17:23:56 +03:00

110 lines
3.0 KiB
C++

//========= Copyright © 1996-2005, Valve Corporation, All rights reserved. ============//
//
// Purpose:
//
//=============================================================================//
#ifndef SHOT_MANIPULATOR_H
#define SHOT_MANIPULATOR_H
#ifdef _WIN32
#pragma once
#endif
#include "mathlib/vector.h"
extern ConVar ai_shot_bias_min;
extern ConVar ai_shot_bias_max;
//---------------------------------------------------------
// Caches off a shot direction and allows you to perform
// various operations on it without having to recalculate
// vecRight and vecUp each time.
//---------------------------------------------------------
class CShotManipulator
{
public:
CShotManipulator( const Vector &vecForward )
{
SetShootDir( vecForward );
};
void SetShootDir( const Vector &vecForward )
{
m_vecShotDirection = vecForward;
VectorVectors( m_vecShotDirection, m_vecRight, m_vecUp );
}
const Vector &ApplySpread( const Vector &vecSpread, float bias = 1.0 );
const Vector &ApplyAngularSpread( const Vector &vecSpread, float bias = 1.0 );
const Vector &GetShotDirection() { return m_vecShotDirection; }
const Vector &GetResult() { return m_vecResult; }
const Vector &GetRightVector() { return m_vecRight; }
const Vector &GetUpVector() { return m_vecUp;}
private:
Vector m_vecShotDirection;
Vector m_vecRight;
Vector m_vecUp;
Vector m_vecResult;
};
//---------------------------------------------------------
// Take a vector (direction) and another vector (spread)
// and modify the direction to point somewhere within the
// spread. This used to live inside FireBullets.
//---------------------------------------------------------
inline const Vector &CShotManipulator::ApplySpread( const Vector &vecSpread, float bias )
{
// get circular gaussian spread
float x, y, z;
if ( bias > 1.0 )
bias = 1.0;
else if ( bias < 0.0 )
bias = 0.0;
float shotBiasMin = ai_shot_bias_min.GetFloat();
float shotBiasMax = ai_shot_bias_max.GetFloat();
// 1.0 gaussian, 0.0 is flat, -1.0 is inverse gaussian
float shotBias = ( ( shotBiasMax - shotBiasMin ) * bias ) + shotBiasMin;
float flatness = ( fabsf(shotBias) * 0.5 );
do
{
x = random->RandomFloat(-1,1) * flatness + random->RandomFloat(-1,1) * (1 - flatness);
y = random->RandomFloat(-1,1) * flatness + random->RandomFloat(-1,1) * (1 - flatness);
if ( shotBias < 0 )
{
x = ( x >= 0 ) ? 1.0 - x : -1.0 - x;
y = ( y >= 0 ) ? 1.0 - y : -1.0 - y;
}
z = x*x+y*y;
} while (z > 1);
m_vecResult = m_vecShotDirection + x * vecSpread.x * m_vecRight + y * vecSpread.y * m_vecUp;
return m_vecResult;
}
inline const Vector &CShotManipulator::ApplyAngularSpread( const Vector &vecSpread, float bias )
{
float x, y, z;
x = vecSpread[0] * random->RandomFloat(-0.5f, 0.5f);
y = vecSpread[1] * random->RandomFloat(-0.5f, 0.5f);
z = vecSpread[2] * random->RandomFloat(-0.5f, 0.5f);
matrix3x4_t matrix;
QAngle qa(x,y,z);
AngleMatrix( qa, matrix );
VectorTransform(m_vecShotDirection, matrix, m_vecResult);
return m_vecResult;
}
#endif // SHOT_MANIPULATOR_H